NORTH HAVERHILL, N.H. -- The husband of a woman fatally shot in a hospital said he saw his stepson point a gun at her and fire several shots before walking away without saying a word, according to a police complaint released Wednesday.

Travis Frink, of Warwick, Rhode Island, pleaded not guilty to a first-degree murder charge in the death of his mother, 70-year-old Pamela Ferriere. He was being held without bail.

Ferriere, of Groton, was fatally shot Tuesday at Dartmouth-Hitchcock Medical Center in Lebanon, where she was being treated for an aneurysm. She was expected to be released Friday.

Frink, 48, was handcuffed and said nothing during the brief arraignment Wednesday in Grafton Superior Court in North Haverhill.

Police respond to the Dartmouth-Hitchcock Medical Center in New Hampshire Sept. 12, 2017

WCAX-TV

Prosecutor Jane Young asked that Frink have no contact with his stepfather, Robert Ferriere, who told police he saw Frink shoot her. Defense lawyer Rebecca McKinnon agreed to the request. She declined to comment afterward.

A police affidavit says Frink told officers he went to the hospital to kill his mother. No reason or motive was given.

When Frink went to visit her Tuesday, Robert Ferriere was in the room and Frink asked to spend some time alone with his mother, authorities said.

Ferriere asked his wife if that was OK and she indicated yes, the affidavit said. As he was leaving the room, he heard her shout or scream something, then turned and saw Frink pointing a gun at her, the affidavit said. After several shots were fired, Frink walked out of the room.

"Frink did not say a word. Frink put the gun in a bag he had been holding and walked" past his stepfather without saying anything, a police report reads.

Pamela Ferriere's nurse called 911, saying a visitor had pulled out a black handgun. When she saw the gun, the nurse ran and took shelter in a different room. She then heard two gunshots, followed by screams.

The hospital, New Hampshire's largest, was then placed on lockdown.

When asked about the shooting Wednesday morning by The Associated Press, Robert Ferriere said he had no idea why it happened. "I'm not a mind reader," he said, before hanging up.

Frink was detained as he tried to leave the grounds of Dartmouth-Hitchcock, authorities said.

The affidavit said Frink also visited his mother earlier in her hospital stay. The nurse who called 911 told police she had been his mother's nurse for the past two weeks.

In 2013, Frink's ex-wife and her 3-year-old son were found dead inside a running car at an apartment complex in Rhode Island.

Police said that when officers opened the door of the running car with fogged windows, they found the inside of the vehicle very hot and smelling of alcohol and vomit. Officials said the body of Kathleen Frink was found in the driver's seat and the body of her son was found on the floor in the back of the car.

Police said at the time they ruled out foul play, and suspected alcohol played in a role.

Frink's Facebook page shows he got engaged last December. His LinkedIn page includes a long list of experience in computer systems administration and technical support jobs in Rhode Island, Connecticut, New York and Massachusetts. Messages left with the company listed as his current employer weren't immediately returned.

Several of Frink's neighbors in Warwick said he mostly kept to himself.

Tuesday's shooting sparked panic at the hospital as employees and patients were evacuated into the parking lot. People were told to avoid the area around the hospital, and traffic was stopped on a route leading to it.

Joanne Conroy, the president of Dartmouth-Hitchcock, praised her staff for its response and said everyone had taken part in several active-shooter trainings in the past.

Dartmouth-Hitchcock Medical Center was back up and running Wednesday. Officials tweeted photos and messages of employees getting back to work.

CEO Joanne Conroy says the medical center is hosting a town hall meeting for employees Wednesday to discuss next steps as workers recover from this "traumatic event."

Officials at Dartmouth-Hitchcock Medical Center say they are reviewing their security procedures but feel comfortable that they can continue to provide a safe environment for patients.